sd-netlink: do not swap old name and alternative name

Commit 434a348 ("netlink: do not fail when new interface name is
already used as an alternative name") added logic to set the old
interface name as an alternative name, but only when the new name is
currently an alternative name. This is not the desired outcome in most
cases, and the important part of this commit was to delete the new name
from the list of alternative names if necessary.

Author: enr0n

src/libsystemd/sd-netlink/netlink-util.c

@@ -3,7 +3,6 @@
 #include "sd-netlink.h"
 
 #include "fd-util.h"
-#include "format-util.h"
 #include "io-util.h"
 #include "memory-util.h"
 #include "netlink-internal.h"
@@ -15,7 +14,6 @@
 int rtnl_set_link_name(sd_netlink **rtnl, int ifindex, const char *name) {
         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL;
         _cleanup_strv_free_ char **alternative_names = NULL;
-        char old_name[IF_NAMESIZE] = {};
         int r;
 
         assert(rtnl);
@@ -35,10 +33,6 @@ int rtnl_set_link_name(sd_netlink **rtnl, int ifindex, const char *name) {
                 if (r < 0)
                         return log_debug_errno(r, "Failed to remove '%s' from alternative names on network interface %i: %m",
                                                name, ifindex);
-
-                r = format_ifname(ifindex, old_name);
-                if (r < 0)
-                        return log_debug_errno(r, "Failed to get current name of network interface %i: %m", ifindex);
         }
 
         r = sd_rtnl_message_new_link(*rtnl, &message, RTM_SETLINK, ifindex);
@@ -53,13 +47,6 @@ int rtnl_set_link_name(sd_netlink **rtnl, int ifindex, const char *name) {
         if (r < 0)
                 return r;
 
-        if (!isempty(old_name)) {
-                r = rtnl_set_link_alternative_names(rtnl, ifindex, STRV_MAKE(old_name));
-                if (r < 0)
-                        log_debug_errno(r, "Failed to set '%s' as an alternative name on network interface %i, ignoring: %m",
-                                        old_name, ifindex);
-        }
-
         return 0;
 }